In genetic engineering and development of medicines in the field of recent medical science, pharmaceutics and others, there is increasing the necessity of transferring a selected molecule, for example, polynucleotides such as genes, proteins, physiologically-active molecules, candidates for medicines and others into cells, followed by inspecting the function of the gene in the cells or the physiological activity of the physiologically-active molecule in them. At present, an electroporation method, a gene gun method, a liposome method, a cell fusion method, a virus vector method and others are employed for transferring selected molecules, but, in any of these, selected molecules could not always be satisfactorily transferred into cells.
The electroporation method and the gene gun method may apply to many cells, but they require complicated operations and are difficult to modify for HTS (high throughput screening). The liposome method is problematic in that the cells to which it may apply are limited. In addition, these methods are all expensive, and even if they could be modified for HTS, they shall be extremely expensive. Further, most of them are not satisfactory in point of the transfer efficiency.
The human and mouse gene arrangements have now been clarified, and it is urgently necessary to analyze the genes having unknown functions so as to clarify their functions. In that situation, it is indispensable to develop a gene transfer method enough for HTS. Even in HTS, it is still desired that the method is efficient and enables functional analysis of various genes. For this, it is also urgently necessary to develop a high-efficiency gene transfer method not for specific limited cells but for various cells.
An object of the present invention is to solve the problems with the related art as above and to provide a high-efficiency method of transferring selected molecules into various types of cells and a method of fusing cells.